An organic light-emitting diode (OLED) display panel achieves the display function by means of OLEDs in respective sub-pixels. An anode and a cathode of each OLED are respectively connected to an anode voltage and a cathode voltage, a difference between the anode voltage and the cathode voltage being a driving voltage, and the larger the brightness of the OLED is, the higher driving voltage is required. In the prior art, the driving voltage for an OLED display panel is provided by a power supply circuit and remains unchanged during display. If the driving voltage needs to be changed, it needs to be reset after the OLED display panel is turned off. Power consumption of the OLED display panel includes two parts, namely, power consumption caused by driving the OLEDs to emit light and power consumption caused by drive transistors of the respective sub-pixels, and the latter power consumption increases with an increase in the driving voltage.
Since the driving voltage remains unchanged, the driving voltage has to be higher than a voltage required for driving the OLEDs to reach the maximum brightness, in order to ensure that the OLEDs can reach the maximum brightness thereof. In this way, when an OLED has a relatively low brightness, the driving voltage is far higher than the voltage required for driving the OLED, thus, most of the power consumption of the drive transistors is unnecessary, as a result, useless power consumption is large and the power supply circuit has low efficiency.